The invention relates generally to group III nitride devices, and more particularly to group III nitride metal oxide semiconductor (MOS) devices.
Electronic devices based on wide bandgap semiconductors offer superior high voltage, high power, high temperature, and high frequency operation. Wide band gap group III nitride semiconductor materials include but are not limited to materials such as gallium nitride, aluminum nitride, and aluminum-gallium nitride materials. For example, gallium nitride (GaN) is a semiconductor material with a wide (3.4 eV) band gap and a high (2500° C.) melting point. GaN is a hard, mechanically stable material with large heat capacity. These properties make it especially suitable for use in a high-frequency, high-power device operated at a high temperature and/or under high-voltage conditions.
High-power metal-oxide-semiconductor field effect transistors (MOSFET) devices are desirable for various power electronic applications. GaN MOSFETs are currently being investigated because of their favorable properties. Gallium nitride based MOSFET devices can provide lower losses than silicon devices. Gallium Nitride based MOSFETs are also expected to have lower gate leakage and potentially higher reliability due to the larger conduction band offset between GaN and SiO2.
Due to the relative ease of growing planar Ga-face C-planes, virtually all MOSFET GaN devices are grown parallel to the polar c-axis. Such devices typically exhibit shifts in device parameters with temperature.
Accordingly, a technique is needed to address problems due to shifts in device parameters with temperature in group III nitride semiconductor devices, such as GaN MOSFET devices.